Is there a way to detect memory fragmentation on linux ? This is because on some long running servers I have noticed performance degradation and only after I restart process I see better performance. ...

I was writing an utility to check /proc/net/tcp and tcp6 for active connections as its faster than parsing netstat output.
As I dont actually have ipv6 enabled I was mainly utilizing localhost as my ...

I have a nice shaper, with hashed filtering, built at a linux bridge. In short, br0 connects external and internal physical interfaces, VLAN tagged packets are bridged "transparently" (I mean, no VLAN ...

I am trying to improve performance on my server. I have a few processes that need low jitter (less than 10ms variance).
I have a load average of 4 maximum on an i7-920 (4 physical cores, 8 with HT). ...

The Server is EC2 Instance, it stands for saving files to NAS (NFS) from HTTPD.
The processes like flush-0:32 consume over %90 of CPU and load average: 65.50, 64.02, 66.59.
According the graph, it's ...

My Server and Client softwares run both on Linux.
The Server broadcasts multicast, the Client listens multicast.
My Client has to migrate to another site,
and unfortunately multicast is not allowed ...

I have a server with CentOS 6.2 with kernel version 2.6.32, but I need to increase my application Performance.
The Kernel Version 3.4 has x32abi which can improve the performance so i want to upgrade ...

I've recently converted some java apps to run with linux manually-configured hugepages, as desribed here. I point out "manually-configured" because they are not transparent hugepages, which gave us ...

Is it possible to view full program command line arguments in OOM killler logs ?
What I see now in /var/log/syslog is
Memory cgroup out of memory: Kill process 29187 (beam.smp) score 998 or sacrifice ...

Folks,
As we know, the 3.x kernels have higher TCP default connection values, such as initcwnd and initrwnd. For 2.x friends, is there a way to set these in /etc/sysctl.conf instead of the ip route ...

I've have an ageing Linux server running on Dell PowerEdge hardware, with a SAS 5IR RAID controller. It has a pair of SAS 146Gb disks in a RAID 1 configuration that has the OS and other software. I ...

I noticed that when serving images Nginx is sending images using both writev() when called from a browser such as Firefox, but uses sendfile() to send the image when wgetting the image. Any idea why ...

Upon issuing a ps ax command on a server I see the following processes that I can't identify. Googling them yields nothing useful. Does anybody know what these are or how I would track them down?
The ...

I've seen sysadmins playing with /proc/sys/vm/drop_caches (echo 3 into this file from a cron) in order to free caches.
Is there a real interrest in doing this? Aren't the clean caches reclaimed when ...

We are developing on a small embedded device. This device us a gumstix overo board running OpenEmbedded linux. We have our development almost completely done, and have run into the strangest of bugs ...

Having just configured Munin for statistics logging on my gentoo server (hardened profile), I am noticing that my "Available entropy" is consitently in the 200-300 range. This seems way to low, so I ...

I have a strange problem that when I run top command it shows that some processes are using around 1.5GB of swap space but then the overall usage of the system swap is way to less to something around ...

its a bit silly Question,
I was thinking since i have some spear HW to install ESXi free edition and allow some external users to use prebuild ubuntu 10.04 servers.
since with kernel updates etc etc ...